- An increase in serum CA 125 level, as defined as follows: 1) normalization of the CA 125 during first-line chemotherapy followed by an increase of >= 100 units/mL; OR 2) normalization of the CA 125 during first-line chemotherapy followed by a doubling of the CA 125 beyond the upper limit of normal with a confirmatory measurement within a period of 4 weeks or less that shows the same or higher CA 125 level